The interactive relationship between the piano and the orchestra in Mozart's concertos is an issue central to the appreciation of these great works, but one that has not yet received serious attention, a gap which this new study seeks to remedy by exploring the historical implications and hermeneutic potential of dramatic dialogue. The author shows that invocations of dramatic dialogue are deeply ingrained in late-eighteenth-century writings on instrumental music, and he develops this theme into an original and highly positive view of solo/orchestra relations in Mozart's concertos. He analyses behavioural patterns in the concertos and links them to theoretical discussion of late-eighteenth-century drama and to analogous relational development in Mozart's operas Idomeneo, Die Entführung aus dem Serail, Le nozze di Figaro and Don Giovanni.Mozart's piano concertos emerge afresh from this new approach as an extraordinary medium of Enlightenment, as significant in their way as the greatest late-eighteenth-century operatic and theatrical works. SIMON P. KEEFE is James Rossiter Hoyle Chair of Music, University of Sheffield.